BIOCONTROL FUNGI FOR CONTROL OF PLANT PATHOGENS: A WHOLE DIFFERENT BIOCONTROL GAME

1. BIOCONTROL FUNGI FOR CONTROL OF PLANT PATHOGENS:A WHOLE DIFFERENT BIOCONTROL GAME ROBERT LARKIN USDA-ARS, New England Plant, Soil, and Water Lab Orono, ME At the USDA-ARS, New England Plant, Soil, and Water Lab, one of our main missions is the development of specific potato cropping systems (and alternative management practices) that are profitable, productive, efficient, that minimize chemical inputs (both fertilizers and pesticides), and promote sustainability. Currently, we are evaluating several different 2- and 3-yr rotations for these characteristics in Northern and Central Maine. My research focuses on the potential effects of these cropping systems on soil microbial ecology and soilborne diseases. Soil microbiology greatly impacts many important soil and plant processes and functions. It is a critical determinant of soil nutrient status, crop health, and overall crop productivity. For example, the prevalence of soilborne pathogens and other deleterious organisms can cause severe disease and/or reduce plant vigor, growth, and crop yields. On the other hand, an abundance of beneficial root and soil organisms can suppress pathogens and disease, improve plant nutrition, promote growth, and increase productivity. Although many factors can affect soil microbiology, including soil characteristics, environmental conditions, and crop management strategies (such as tillage, cultural practices, agric. chemicals used, etc.), one of the most important factors driving changes in soil microbiology is the specific plant species present (both crops + weeds). It is known that the specific crops grown greatly affects soil microbiology. Yet, relatively little is known about the precise nature of these changes, how they occur, and what their effects are? However, a better understanding of the relationships among specific cropping systems (and other management strategies), their resultant changes in soil microbial ecology, and their roles and effects on crop health and productivity is necessary for the development of more efficient, sustainable crop production systems. At the USDA-ARS, New England Plant, Soil, and Water Lab, one of our main missions is the development of specific potato cropping systems (and alternative management practices) that are profitable, productive, efficient, that minimize chemical inputs (both fertilizers and pesticides), and promote sustainability. Currently, we are evaluating several different 2- and 3-yr rotations for these characteristics in Northern and Central Maine. My research focuses on the potential effects of these cropping systems on soil microbial ecology and soilborne diseases. Soil microbiology greatly impacts many important soil and plant processes and functions. It is a critical determinant of soil nutrient status, crop health, and overall crop productivity. For example, the prevalence of soilborne pathogens and other deleterious organisms can cause severe disease and/or reduce plant vigor, growth, and crop yields. On the other hand, an abundance of beneficial root and soil organisms can suppress pathogens and disease, improve plant nutrition, promote growth, and increase productivity. Although many factors can affect soil microbiology, including soil characteristics, environmental conditions, and crop management strategies (such as tillage, cultural practices, agric. chemicals used, etc.), one of the most important factors driving changes in soil microbiology is the specific plant species present (both crops + weeds). It is known that the specific crops grown greatly affects soil microbiology. Yet, relatively little is known about the precise nature of these changes, how they occur, and what their effects are? However, a better understanding of the relationships among specific cropping systems (and other management strategies), their resultant changes in soil microbial ecology, and their roles and effects on crop health and productivity is necessary for the development of more efficient, sustainable crop production systems.

2. Biocontrol of plant pathogens and disease is fundamentally different from biocontrol of weeds, insects, or other animals. Emphasis is placed on disease control rather than pathogen control, and in some cases the pathogen is not targeted at all. Thus, very different characteristics are involved, and this biocontrol only rarely resembles the traditional approach of using debilitating pathogens or parasites to destroy a target organism. These characteristics have important implications on the potential impacts of these biocontrol agents and approaches. At the USDA-ARS, New England Plant, Soil, and Water Lab, one of our main missions is the development of specific potato cropping systems (and alternative management practices) that are profitable, productive, efficient, that minimize chemical inputs (both fertilizers and pesticides), and promote sustainability. Currently, we are evaluating several different 2- and 3-yr rotations for these characteristics in Northern and Central Maine. My research focuses on the potential effects of these cropping systems on soil microbial ecology and soilborne diseases. Soil microbiology greatly impacts many important soil and plant processes and functions. It is a critical determinant of soil nutrient status, crop health, and overall crop productivity. For example, the prevalence of soilborne pathogens and other deleterious organisms can cause severe disease and/or reduce plant vigor, growth, and crop yields. On the other hand, an abundance of beneficial root and soil organisms can suppress pathogens and disease, improve plant nutrition, promote growth, and increase productivity. Although many factors can affect soil microbiology, including soil characteristics, environmental conditions, and crop management strategies (such as tillage, cultural practices, agric. chemicals used, etc.), one of the most important factors driving changes in soil microbiology is the specific plant species present (both crops + weeds). It is known that the specific crops grown greatly affects soil microbiology. Yet, relatively little is known about the precise nature of these changes, how they occur, and what their effects are? However, a better understanding of the relationships among specific cropping systems (and other management strategies), their resultant changes in soil microbial ecology, and their roles and effects on crop health and productivity is necessary for the development of more efficient, sustainable crop production systems. At the USDA-ARS, New England Plant, Soil, and Water Lab, one of our main missions is the development of specific potato cropping systems (and alternative management practices) that are profitable, productive, efficient, that minimize chemical inputs (both fertilizers and pesticides), and promote sustainability. Currently, we are evaluating several different 2- and 3-yr rotations for these characteristics in Northern and Central Maine. My research focuses on the potential effects of these cropping systems on soil microbial ecology and soilborne diseases. Soil microbiology greatly impacts many important soil and plant processes and functions. It is a critical determinant of soil nutrient status, crop health, and overall crop productivity. For example, the prevalence of soilborne pathogens and other deleterious organisms can cause severe disease and/or reduce plant vigor, growth, and crop yields. On the other hand, an abundance of beneficial root and soil organisms can suppress pathogens and disease, improve plant nutrition, promote growth, and increase productivity. Although many factors can affect soil microbiology, including soil characteristics, environmental conditions, and crop management strategies (such as tillage, cultural practices, agric. chemicals used, etc.), one of the most important factors driving changes in soil microbiology is the specific plant species present (both crops + weeds). It is known that the specific crops grown greatly affects soil microbiology. Yet, relatively little is known about the precise nature of these changes, how they occur, and what their effects are? However, a better understanding of the relationships among specific cropping systems (and other management strategies), their resultant changes in soil microbial ecology, and their roles and effects on crop health and productivity is necessary for the development of more efficient, sustainable crop production systems.

3. With this in mind, the objectives of the studies we have initiated on cropping systems effects on soil microbiology are as follows; OBJECTIVES: > Evaluate the influence of potato cropping systems and other management strategies on soil microbial ecology. > Determine the implications and roles of changes in soil microbial communities on disease management, crop health, and crop productivity With the ultimate goal down the road being to : > Determine the best management approaches for optimizing the soil microbial environment for improved, sustainable crop production With this in mind, the objectives of the studies we have initiated on cropping systems effects on soil microbiology are as follows; OBJECTIVES: > Evaluate the influence of potato cropping systems and other management strategies on soil microbial ecology. > Determine the implications and roles of changes in soil microbial communities on disease management, crop health, and crop productivity With the ultimate goal down the road being to : > Determine the best management approaches for optimizing the soil microbial environment for improved, sustainable crop production

4. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

5. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

6. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

8. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

9. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

10. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

11. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

15. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.

16. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms. METHODOLOGY: In order to determine effects on soil microbial communities, a variety of different approaches and methodologies are needed to assess and characterize different aspects of these complex communities. In this study, we assessed traditional parameters, such as overall populations of culturable microorganisms using soil dilution plating on general and selective media, and overall microbial activity to give a general indication of gross changes in microbial characteristics. In addition, we tried to assess some functional attributes of the communities using sole carbon source substrates (substrate utilization profiles) to determine differences in abilities to utilize different nutrient sources. Individual organisms were identified to genus and species (by fatty acids) to determine the taxonomic composition and diversity of organisms present. And structural attributes of the communities were assessed by soil community fatty acid profiles, which is a community-level approach that includes assessment of nonculturable organisms.